Outside influences on running have more of an impact than we think. And because it's not tangible or easy to recognise, we tend to dismiss it in our heads and treat any shortfall in performance as a failure of training or a lack of fitness.
This is usually far from the case, particularly if you have kept on top of your running and are doing so in a sustainable way (Not running every run at a moderate speed, getting your recovery and the right volume and intensity of speed work in).
External stresses relating to anything from family to financial concerns, or the broader lockdown fatigues us mentally, even if we don't feel like it is. There is a limit to the amount of stress anyone can handle, so the more non-running related stress there is in your life, the less running you'll be able to handle without experiencing overtraining fatigue.
Conversely, don't make running a source of stress either. If you're training for a marathon but the level of physical and mental commitment required to do that is dragging you down, then reassess what value it has in your life, and perhaps take a step back to focus on things more important (Which to be honest, is a lot of things in life).
Don't be afraid to take that step back, reevaluate and do things that keep you happy. Cameron Harris- Head Coach